ProSelect uses the name of your computer when checking for correct activation on a machine. If your computer is activated under one name "My Mac" and you change the name to "Your Mac" it will think that ProSelect has been installed on a different computer and request that you activate ProSelect again.

So if you are changing your computer's name it is best to Deactive ProSelect before change the name using this option under the Help menu. Then change the name and re-active it again after that.

There can also be some circumstances where the name of your computer will change automatically causing activation problems.

Typically this is where the name changes from a name such as "My Computer" to "My Computer (2)" or "My Computer (3)".

This can happen if:

1. You have more than one computer with the same name connected to your local network. 
2. You switch network connections on your computer (eg from ethernet to wireless) without turning the first one off BEFORE you turn the second one on.
3. You have installed an operating system upgrade in the past using the "Archive & Install" option and the old copy of the operating system is in the "Previous Systems" folder at the top level of your hard disk. In this case, try trashing the folder and emptying the trash.

You can see the current name of your computer under OSX's System Preferences -> Sharing.

We have made a change to the Mac version of ProSelect 2011r1.9 (and newer) to get around the activation problems that can occur if OSX changes your computer name.